The use of catheters for minimally invasive medical procedures has become widespread. In many such procedures, a guidewire is used to help place the distal end of a catheter at a desired location. In practice, the use of a guidewire and an elongate medical device such as a catheter can create a number of difficulties.
If a guidewire or catheter proves unsuitable once inserted into a patient, it is removed and replaced. With early technologies, the catheter typically tracked over the guidewire along its entire length. When a catheter was removed, these early technologies required allowing the entire length of the catheter (typically 150 cm or longer) to pass over the guidewire without releasing the proximal end of the guidewire. This required a guidewire having a length of at least 300 cm, or a shorter guidewire used in combination with a guidewire extension. Such long guidewires required extra hands in the operating arena, increasing costs and creating a greater risk of loss of sterility, as well as making procedures last longer.
Rapid exchange catheters and single operator exchange catheters have been developed to make it easier and quicker to substitute one catheter or guidewire for another. An example single operator exchange catheter is the Autotome™ RX sphincterotome, marketed by Boston Scientific Corporation, Natick, Mass., which makes use of an elongated guidewire lumen in the form of a C-shaped channel.
The C-shaped channel allows lateral movement of a guidewire out of the guidewire lumen through the opening in the C-shaped channel over the longitudinal length of the channel. Such an opening, as well as openings or accesses created by the use of C-shaped, U-shaped, perforated or slit guidewire lumens, makes the longitudinally extending guidewire lumen a laterally accessible guidewire lumen. Lumens having a weakened, thin, or thinned wall through which a guidewire may tear for removal may also be considered as including a laterally accessible guidewire lumen.